Bending various proprietary devices to our will is a hacker’s rite of passage. When it comes to proprietary wall sockets, we’d often reverse-engineer and emulate their protocol – but you can absolutely take a shortcut and, like [oaox], spoof the button presses on the original remote! Buttons on such remotes tend to be multiplexed and read as a key matrix (provided there’s more than four of them), so you can’t just pull one of the pads to ground and expect to not confuse the microcontroller inside the remote. While reading a key matrix, the controller will typically drive rows one-by-one and read column states, and a row or column driven externally will result in the code perceiving an entire group of keys as “pressed” – however, a digitally-driven “switch” doesn’t have this issue!
One way to achieve this would be to use a transistor, but [oaox] played it safe and went for a 4066 analog multiplexer, which has a higher chance of working with any remote no matter the button configuration, for instance, even when the buttons are wired as part of a resistor network. As a bonus, the remote will still work, and you will still be able to use its buttons for the original purpose – as long as you keep your wiring job neat! When compared to reverse-engineering the protocol and using a wireless transmitter, this also has the benefit of being able to consistently work with even non-realtime devices like Raspberry Pi, and other devices that run an OS and aren’t able to guarantee consistent operation when driving a cheap GPIO-operated RF transmitter.
In the past, we’ve seen people trying to tackle this exact issue, resorting to RF protocol hacking in the end. We’ve talked about analog multiplexers and switches in the past, if you’d like figure out more ways to apply them to solve your hacking problems! Taking projects like these as your starting point, it’s not too far until you’re able to replace the drift-y joysticks on your Nintendo Switch with touchpads!
In the world of Doctor Who, the sonic screwdriver is a versatile tool with a wide range of capabilities. [Hartley] wanted some of that action for himself, and built a device of his own.
Unable to recreate the broad swathe of features from the show, he settled on something easier. The device is fitted with an ATTiny85, and a 433MHz transmitter. It’s programmed to switch wirelessly controlled mains sockets on and off. This lets him control appliances in his house with a flick of a screwdriver. Power is supplied by the classic AA battery, with a boost converter stepping it up to 5V to run the electronics.
It’s all wrapped up in a 3D printed case, that was carefully designed to fit all the parts inside. A paper mockup of the PCB layout was also used in the design phase. [Hartley] took full advantage of CAD software, to ensure everything fit correctly first time.
It’s a fun project, as sonic screwdrivers often are. Video after the break.
Continue reading “Sonic Screwdriver Shuts Off Mains”
Amazon Alexa, Google Home, and just about every electronic device manufacturer are jumping on the bandwagon of connected devices. They promise us the ability to turn on our toaster from another room, unlock our doors just by shouting at them from outside, and change the channel on our TV through perfectly enunciating a sentence instead of mashing the buttons on our remotes like chumps. And yet, despite all this new-fangled finger-less control, there is an unanswered question: does this technology save us energy in the long run?
For years we’ve been hearing about vampire power and all the devices in our home that sit in standby, waiting for their masters to turn them on, quietly burning power to listen for that signal to wake. Fortunately the One Watt Initiative and general awareness and design for energy savings has cut out a lot of this phantom load. So how does the smart home, which essentially adds a bunch of connected vampires to our base load, end up saving money in the long run? And is it better than other alternatives or just good habits? I put these questions to the test with today’s smart power strips and controllable outlets.
Continue reading “Smart Plugs Don’t Save You Energy, But Don’t Consume Much Either”
[Joedefa] had a Griffin Beacon Universal Remote that was collecting dust, and decided that it needed to stop collecting dust. He had a growing number of wireless devices in his house and found himself in need of a remote to control them all. The Griffin Beacon fit the bill, but most of his lights and outlets were RF controlled. So he did what hackers do best… broke out the screw driver and soldering iron and rewired it!
[Joedefa] is using an Attiny85 as the brains between an infrared LED and a RF transmit module (if anyone can identify the source of this module, please let everyone know in the comments). A pair of red and green LEDs lets him know if the remote has received commands successfully.
It’s always nice to see a discontinued product made useful once more with a little ingenuity and
an Arduino some hacking skill. Hat’s off to [Joedefa] for a righteous hack!
[Reza’s] methodical investigation of this remote controlled outlet let him patch in with an Arduino using a 433 MHz transmitter. This is a single-device unit, but the techniques used here should allow you to take control of wireless rigs that have multiple modules to control many devices.
We’ve seen some folks at our local hackerspace try to patch into the remote control itself. That used some type of weird button scanning (not just connecting a pin to ground or voltage) and didn’t pan out. [Reza] doesn’t even crack open the case of either of the units seen above. Instead, he goes straight for a wireless receiver he had on hand, using a logic analyzer to capture the signals coming from the remote.
Once he had a good snapshot of the signals sent when pressing the on or off button of the remote he set out to replicate it in his Arduino code. His function called setStateWithDelay takes three parameters: the transmit pin, the level (high or low), and a number of milliseconds to delay. Each signal calls this function many times, but working the bugs out is pretty easy; just capture the signal with the logic sniffer and compare to the stock remote.